Added in Commerce 0.3, the TaxJar module provides an integration with the TaxJar API for fully automated and highly accurate US Sales Tax calculations.
To access the TaxJar API, a Professional account is needed starting at $99 per month. In return, you don't have to worry about figuring out appropriate destination and sender based sales tax rates.
When enabling the TaxJar module, it will be available as a Rate Provider for your Tax Rules.
The taxjar properties are managed as system settings. Go to System > System Settings, choose commerce as namespace, and TaxJar as area, to find all the below options.
TaxJar API Token (
commerce.taxjar.api_key): this is provided by TaxJar under Account > Data sources > TaxJar API.
Nexus Country (
commerce.taxjar.nexus_country): the country from where you sell or ship your products, defaults to US.
Nexus State (
commerce.taxjar.nexus_state): the state from where you sell or ship your products.
Nexus Zip (
commerce.taxjar.nexus_zip): the zipcode from where you sell or ship your products.
Nexus City (
commerce.taxjar.nexus_city, added in v1.2): the city from which you sell or ship
Nexus Street (
commerce.taxjar.nexus_street, added in v1.2): the street (address line) from which you sell or ship
If you have more than one Nexus, you can add those to your TaxJar account and they'll be taken into consideration as well.
As of Commerce v1.2, the TaxJar will use rooftop-level accuracy for sales tax rates, based on the street and city provided by the customer.